- [[Newton's Law of Universal Gravitation]] - acceleration of gravity: - About $9.8 m/s^2$ downward (near Earth's surface) - does not depend on mass of object - every object accelerates that much downward on Earth - (weight) force of gravity: - the force of gravity from the Earth acting on an object with mass $m$ is - $F = mg$ - $g$ is the magnitude of gravitational acceleration ($9.8 m/s^2$ as stated above) - [[Albert Einstein|Einstein]] argued that in reality there is no attraction between [[Mass|Masses]] unlike what [[Isaac Newton|Newton]] proposed - rather objects with [[Mass]] distort [[Spacetime]] around themselves - [[Albert Einstein|Einstein]] also said that gravity acts as the speed of [[Light]]